So my CBS told me that the front pads are due in 13k and rears in 15k...and that was 3k miles ago. They had been counting down until recent dealer visit. So my 4 years is up in March and have been a little over aggressive to make sure they get replaced before then. What gives?

Also since the 135i plugs are due at 45K they are covered by BMW is occurs within the 4 years, right?

You give no indication of your avergae mileage a month, so there is really no way for us to try to help??? we also need to know the mileage on your first set of brakes, so we can compare.

spark plugas are due at appro 45k, it should come up for you to do in time.

FYI Brand new brake pads are like 11 or 12 mm thick.. the sensor triggers at 3 mm so maybe you can pop a wheel off and take a measure... ( its the distance from the rotor to the backing plate. dont include the backing plate)

WOW... you downshift around town, dont you...LOL 41K on originals... thats super duper high... by the math, 9 months to go...1k a month means you may come up short, BUT i have seen as it gets closer, to the max wear limit the miles come off fast...

Take a couple of HPDE events... that will clear your brake wear issue right up.